California Mastitis Test Score Research Articles

Evaluation of the health status of mammary glands and compositional changes in udder-half milk obtained from dairy goats for milk quality management.

This study evaluated the health status of the mammary glands and milk composition of dairy goats. The California mastitis test (CMT) score, somatic cell counts (SCCs), somatic cell type, electrical conductivity (EC), N-acetyl-β-d-glucosaminidase (NAGase) activity, mastitis-causing pathogens, and milk composition in 121 udder-half milk samples from 62 crossbreed goats (1-3years old) at 23-45 days postpartum were compared in four categories with SCCs of <200 × 103 , <300 × 103 , 301-1000 × 103 , and >1010 × 103 cells/ml. The SCC, CMT score, EC, and NAGase activity were significantly lower (p < 0.05) in udder-half milk with SCCs of <200 × 103 and <300 × 103 cells/ml than those in milk with SCCs of 301-1000 × 103 and >1010 × 103 cells/ml. The protein, lactose/ash, and solids-not-fat (SNF) in milk with an SCC of <300 × 103 cells/ml were similar to the previously reported values. The proportion of polymorphonuclear neutrophils was significantly higher (p < 0.05) in milk with SCCs of 301-1000 and >1010 × 103 cells/ml than in milk with an SCC of <300 × 103 cells/ml. Assessing mammary gland health and milk composition based on categorization of udder-half milk by SCC may be useful for milk quality control on goat farms.

Virulence Factors and Prevalence of Udder´s Pathogens in Dairy Cows during the Peripartal Period

Data presented in this study described the prevalence of udder pathogens and presence of virulence factors in staphylococci isolated from mastitis in dairy cows. The practical part of study was realized in five different dairy herds of Slovak spotted cattle breed located in Eastern Slovakia with conventional (non-organic) farming. At the beginning of lactation (during first two months after calving) were comprehensively investigated 960 cows from monitored herds. The comprehensive examination included clinical examination, sensory analysis of milk from fore stripping of each udder quarter, followed by assessment of the California mastitis test (CMT) and laboratory analyses of bacteria pathogens. Screening the health status of the mammary gland revealed that 314 cows (32.7%) had positive CMT score (1-3) for one or more quarters. Out of 230 infected milk samples, representing 24.0% of all dairy cows examined, were the most commonly isolated staphylococci (59.1% of positive findings), followed by E. coli (11.3%), streptococci Str. uberis (9.1%), Str. agalactiae (3.4%), and enterococci (6.1%). From 136 isolates of coagulase negative stafylococci (98 isolates) and S. aureus (38 isolates) were detected some virulence factors such as production of hemolysins (lysines ß and δ), gelatinase, biofilm, and hydrolyze of DNA. Isolated S. aureus, S. chromogenes and S. warneri had the most numerous representation of detected virulence factors, as demonstrated by the increased incidence of clinical forms of mastitis compared to less virulent strains.

Post-dipping in Milk Production, Composition, and Quality

This study aimed to evaluate the influence of post-dipping on milk production, composition, and quality of cows with subclinical mastitis. Samples of mast milk from two different dairy farms were analyzed in two moments: before the post-dipping implantation and after 30 days, the samples were conditioned to the refrigeration temperature in an isothermal box and sent to the laboratory for the following analyzes: California Mastitis Test (CMT), Somatic Cell Count (SCC), Fat, Protein, Lactose, Total Solids (TS), Non-Fat Solids (NFS) and microbiological tests, as well as individual milk weighing. The experimental design was completely randomized and arranged in a split-plot scheme, submitted to analysis of variance (ANOVA) by the F test. The post-dipping practice during 30 days resulted in the means and standard deviation of the analyzes of the studied variables, where the values of SCC, CMT, and microbiological score profile were statistically significant. The highest etiological agent found was Staphylococcus spp. The fat and lactose profile increased in both farms, but there was no significant difference. Protein increased in both farms, but in farm I, there was no significant difference and in farm 2, there was a significant difference. Total Solids, Non-greasy solids, and weighing had a percentage increase, but the means of weight did not differ statistically. The post-dipping technique was an effective measure in the control of subclinical mastitis and brings health benefits to the mammary gland.

Detection of subclinical mastitis in camels (Camelus dromedarius) using somatic cell count, N-acetyl-β-D-glucosaminidase and lactate dehydrogenase activity

Clinical and subclinical mastitis (SCM), mostly related to intramammary infection (IMI), is prevalent in pastoralist camel herds. An IMI has implications for public and animal health as well as for household economy. As bacterial culturing is expensive, time consuming and impractical in a pastoralist setting, other early detection methods for SCM in camels need to be investigated. Somatic cell count (SCC) is the standard for detecting SCM in cattle. The udder health indicators of N-acetyl-β-D-glucosaminidase (NAGase) and lactate dehydrogenase (LDH) activity are useful as diagnostic markers in cow, sheep and goat milk; they could be of potential use in camel milk production. The aim of this study was to improve the understanding of SCM in camels, and specifically to assess SCC, and NAGase- and LDH activity in camel milk. In addition, potential associations between SCM (defined by a California Mastitis Test (CMT) score ≥3 and no signs of clinical mastitis) and SCC, NAGase- and LDH activity were investigated. In total, 40 healthy camels without clinical mastitis were sampled in four herds in Kenya. Quarter milk samples were collected aseptically and screened using CMT. SCC was analysed using a direct cell counter (DCC, DeLaval), and NAGase and LDH activity was analysed using kinetic fluorometric measures. In total, 116 milk samples were tested with CMT and analysed for SCC. Of these, 88 were analysed further for NAGase and LDH. The median SCC was 151,000 cells/mL (IQR: 49,500–709,000 cells/mL), and median NAGase and LDH were 18.5 U/l (IQR:14.8–24.0 U/l) and 12.0 U/l (IQR: 8.5–16.2 U/l) respectively. All inflammatory markers (SCC, NAGase, LDH) were significantly associated with SCM (P < 0.001). In conclusion, SCC, NAGase and LDH are potential inflammatory indicators in camel milk that can be used for detection of udder quarters with SCM.

Intercurrence between bovine leukosis virus infection and mastitis in dairy cattle

There are several factors affecting global milk production leading to severe economic losses. Mastitis and leukosis are highly prevalent diseases especially in Brazilian cattle herds. The present study aimed to evaluate the correlation between mastitis and the bovine leukemia virus (BLV) infection in naturally infected cows belonging to dairy herds in Minas Gerais State. Additionally, the prevalence of both diseases, pathogens causing mastitis, and their association with BLV infection and persistent lymphocytosis were evaluated. The prevalence of BLV was determined using the agar gel immunodiffusion test (AGID) in 1,392 lactating cows from ten dairy herds. From the AGID results, 240 cows were selected and divided into two experimental groups: A case group composed of 160 BLV-positive cows (BLV-P) and the control group of 80 BLV-negative cows (BLV-N). Based on serological and leucocytic evaluations, the animals were classified into three subgroups: BLV-N, BLV-P without persistent lymphocytosis (BLV-PWPL), and BLV-positive with persistent lymphocytosis (BLV-PPL). The California Mastitis Test (CMT) was performed on days 0 (D0) and 60 (D60) in the subgroups and the milk from CMT-positive glands were analyzed. BLV infection was present in 100% of herds, with an overall prevalence of 80.9% in cows older than 24 months. Among BLV-P animals, 74% were classified as BLV-PWPL and 26% as BLV-PPL. Coagulase-negative Staphylococcus (73.30%),Corynebacterium spp. (12.04%), Streptococcus agalactiae (8.90%), and Staphylococcus aureus (5.76%) were predominant (61.41%). There were no statistical differences among the scores of clinical or subclinical mastitis with the pathogen type (contagious or environmental) in the BLV-PWPL or BLV-PPL subgroups. However, BLV-P animals showed higher CMT scores than BLV-N animals, suggesting a higher redisposition to subclinical mastitis in cows affected by leukosis.

Therapeutic evaluation of Murraya koenigii in bovine subclinical mastitis

The present study was aimed to evaluate Murraya koenigii leaves for in vitro antibacterial activity of its hydro-alcoholic extract against common bovine mastitogens, and thereafter, in vivo therapeutic efficacy in subclinical mastitis affected dairy cows. The final yield of herbal extract (g/ 100g of herb) from M. koenigii leaves was 7.8%. The antibacterial activity of the hydro-alcoholic extract in terms of the average zone of inhibition shown by M. koenigii against S. aureus and E. coli were 14.13 mm and 16.00 mm respectively and the respective minimum inhibitory concentration was 31.25 mg/ml and 125 mg/ml. In vivo therapy of the herb against specific subclinical mastitis of cows revealed significant decline in total bacterial count, California Mastitis Test score, Somatic Cell Count, electrical conductivity, pH and lymphocytes while there was significant increase in milk neutrophils, and effect on the elimination of intra mammary infections (50.00%) against control (25.00%) on day 28 of treatment was found non-significant (&chi;2 at 01df, N=64 = 1.641, p &gt; 0.5). Therapy with M. koenigii showed significant effect on minimizing the udder inflammation and improvement of milk quality; however, nonsignificant effect on elimination of intra mammary infections warrants more research while using this herb or its pure active constituents in bovine sub-clinical mastitis.

Randomized controlled field trial comparing quarter and cow level selective dry cow treatment using the California Mastitis Test

Selective use of antibiotic dry cow treatment can be implemented at the cow or quarter level, with the latter having the potential to further reduce antibiotic use. Our objective was to compare these 2 approaches in 6 herds in the United Kingdom in which environmental mastitis predominated. Eight hundred seven cows were enrolled and categorized as having a high cell count (n = 401) or low cell count (n = 406) in the last 3 mo of lactation and clinical mastitis history. All quarters of all enrolled cows received an internal teat sealant. Within each category, cows were randomly allocated to 1 of 3 groups; in one group antibiotic treatment was allocated at cow level (i.e., all 4 quarters received antibiotic), whereas in the 2 remaining groups antibiotic treatment was allocated at quarter level, based on California Mastitis Test (CMT) findings. Two different thresholds, score 1 and 2, were used to determine likely infection status. Quarter milk samples were collected at dry off and postcalving for bacteriological culture and somatic cell count (SCC). Cows were monitored for clinical mastitis from dry off until 100 d in milk. Cow level SCC and milk yield data were collated from farm records. Within each category, the 2 quarter level treatment groups were compared with cow level treatment at dry off. Leaving quarters untreated with intramammary antibiotic in cows in the high cell count group, with a CMT <2 or <1, reduced antibiotic use by 55% and 31%, respectively, and resulted in no difference in the odds of being infected with any pathogen postcalving, but was associated with a higher SCC at the first test day. Intramammary antibiotic treatment of quarters with a CMT ≥1 in cows in the low cell count category at dry off was not associated with any reduction in the odds of being infected with a major pathogen postcalving but was associated with a decrease in the odds of being infected with a minor mastitis pathogen postcalving. The use of antibiotics in quarters of cows categorized as low cell count at dry off, increased the proportion of quarters treated with antibiotic from 0% at cow level to 31% (CMT ≥ 1) and 12% (CMT ≥ 2) at quarter level, only resulting in a reduction in SCC of around 20,000 cells/mL at the first test day, if all quarters with CMT score ≥1 were treated with antibiotic. No differences in clinical mastitis incidence and milk yield in the first 100 d in milk were detected between any of the treatment groups. These study findings support selective quarter level dry off treatment only in cows with cow level SCC >200,000 cells/mL at dry off.

Effect of Extra-mammary Diseases on Udder Health and Biochemical Changes in Crossbred Cows with Subclinical Mastitis

Background: Infectious diseases and metabolic disorders are common in crossbred cows and adversely affect optimum production as well as quality of milk. The quality of milk plays a significant role in the production of high-quality dairy products. High somatic cell count (SCC) in the milk significantly decreases the potential of such milk for the production of high quality dairy products. In this study, it is hypothesized that the extra-mammary infections and metabolic disorders increase probability of intra-mammary infections thereby increasing somatic cell count in the milk making it unsuitable for dairy industry.Methods: Cows were grouped based on the diseases or disorders like Teat Stenosis (Gp SCM-TS), Ruminal Acidosis (Gp SCM-RA), Nonspecific Diarrhea (Gp SCM-ND), Respiratory Tract Infections (Gp SCM-RTI) and Repeat Breeder Syndrome (Gp SCM-RD). Diagnosis of subclinical mastitis was made on the basis of California Mastitis Test (CMT) scores and by Somatic Cell Count (SCC) by automatic somatic cell counter. Biochemical parameters analyzed in automatic biochemical analyzer using commercially available kits.Result: The mean SCC values significantly higher in cows with sublinical mastitis and with concurrent infectious and metabolic diseases. Similarly, the concentrations of serum alkaline phosphatase (ALP), aspartate amino transferase (AST), and alanine amino transferase (ALT) were higher in affected cows. Concentrations of serum total proteins (TP) and blood urea nitrogen (BUN) in all the groups of affected animals were higher. The changes in the calcium (Ca) and phosphorus (P) levels were not observed in cows with subclinical mastitis and with other diseases under study. The SCC values did not correlate with the values of ALP, AST, ALT, TP, BUN, Ca and P among the studied groups. It can be concluded that animals with concurrent infections and metabolic disorders increase the SCC and influence the alteration in the biochemical parameters of subclinical mastitic animals.

Effect of heat stress amelioration through open-ridge ventilated thatched roof housing on production and reproduction performance of crossbred Jersey cows

The present study was conducted to assess the impacts of loose house roofing designs and materials on modulation of micro-climate of the cow shed and its influences on production and reproduction performance of lactating crossbred Jersey cows. The control group (T0) was kept in a traditional single-slope asbestos roof shed and treatment group (T1) at a specially designed open-ridge ventilated, double-slope thatch roof shed. Lactation stage, average daily milk yield, and average parity at the beginning of the experiment were kept similar between T0 and T1 cows. The specifically designed T1 shed had significantly (P < 0.05) lower temperature, humidity, and thermal humidity index as compared to the traditional shed (T0). The T1 shed was cooler and more comfortable than T0. Housing significantly (P < 0.05) influenced cardinal physiological parameters of resident cows. Body temperature, pulse rate, respiration rate, and discomfort index were significantly (P < 0.05) higher in T0 as compared to those in T1 cows. Improved housing significantly (P < 0.01) influenced milk yield, composition, quality, and udder health of cows. Daily milk yield depending on parity, monthly milk yield, milk fat, SNF, and protein were significantly (P < 0.01) higher in T1 than those in T0 cows. The milk somatic cell count, modified California mastitis test score, electrical conductivity, and pH of milk samples of T0 cows were significantly (P < 0.0) higher than those of T1. Effect of housing type, parity, and interaction of housing × parity did not cause any significant (P > 0.05) differences in reproductive traits such as service period, break period, calving interval, pregnancy rate, and other cow fertility parameters. Post-partum body condition score and body weight loss did not differ significantly (P > 0.05) between the two groups; however, more loss occurred in T0 than T1. The estimated net profit from housing of cows (N = 20) in a comfortable shed was 2200kg milk per annum, i.e., 110kg/cow/annum. The study concluded that a central open-ridge ventilated, double-slope thatched roof design created a favorable micro-environment and it significantly affected cows' comfort index; thermo-comfortable housing significantly reduced the heat stress-oriented drop in milk yield and decline in milk composition, and improved udder health and other milk production traits; however, its impact was non-significant on reproduction and fertility traits in Jersey crossbred cows.

Infectious aetiologies of subclinical bovine mastitis and antimicrobial susceptibility on northwest of Algeria

Subclinical mastitis is one of the most common and expensive diseases in dairy cattle farming, the financial losses caused by mastitis can have a serious effect on economy of dairy industry. Inflammation of mammary gland is a multifactorial and complex disease; the infection can be caused by a large range of pathogenic germs. The objective of this study was to carry out a screening of subclinical mastitis by California mastitis test and to determine the infectious aetiology. A score ≥ 1 was considered positive. 135 milk samples were examined by California mastitis test for mastitis detection, from which 42 samples were found positive and were subjected to bacteriological analysis by standard biochemical tests, in addition an antibiotic sensitivity test was done on bacterial isolate. The prevalence of subclinical mastitis was 31.1% in quarters level and 62.8% in dairy cows, hindquarters were the most infected 35% compared to forequarters 27%. the frequency of infected quarters according to California mastitis test scores 1, 2 and 3 was 7.4%, 14.8% and 8.8% respectively, the most isolated germs from the samples were coagulase negative staphylococci (39%), Enterococcus faecium (10%), Klebsiella pneumoniae (7%) and Enterobacter cloacae (7%), and Enterococcus faecalis (7%). Staphylococcus spp showed a high sensitivity 100% to erythromycin, trimethoprim and neomycin, and lower sensitivity of 33% to amoxicillin. The Enterobacteriaceae exhibited a medium sensitivity of 50% to only trimethoprim and were resistant to other antibiotics.

Relationship Among NAGase Enzyme Activity, CMT Score and Somatic Cell Count in Milk of Crossbred Dairy Cows with Sub-Clinical Mastitis in North-Western Province of Sri Lanka

The assay procedure for N-acetyl-β-D-glucosaminidase (NAGase) was considered to be the most reliable, simple, and rapid enzymatic method for estimating the severity of mammary tissue damage. This study was carried out to assess the relationship of NAGase enzyme activity, California mastitis test score (CMTS) and somatic cell counts (SCC) in milk and the influence of breed, parity and age of the cow on NAGase activity. The results showed that prevalence of sub-clinical mastitis (SCM) was 74.5% (41/55) in the population of cows tested. The isolated pathogens were Staphylococcus spp. (34%, 14/41), Escherichia coli (34%, 14/41) and Streptococcus spp. (32%, 13/41). The SCC showed a significant (p<0.05) positive correlation with the activity of NAGase (R2= 0.796) and CMTS (R2= 0.709). A significant correlation was observed between the NAGase activity and SCC in SCM positive milk, where the correlation was stronger (R2= 0.748) in the former than in the latter. The parity (R2= 0.843) and age (R2= 0.758) of the cow also showed a significant (p<0.05) positive correlation with enzyme activity. The mean SCC and enzyme activity of different crossbreds of the study population did not show a significant correlation, but mean values of SCC and enzyme activity were higher when an animal was phenotypically more related to European breeds (779– 1848 x103 SCC/ml;0.64 -0.89 μmole/min/ml) than tropical breeds (427–534x103 SCC/ml; 0.26-0.43 μmole/min/ml). It could be concluded that, the prevalence of SCM in crossbred cows in North-Western Province of Sri Lanka is considerably high. The determination of NAGase enzyme activity in milk could be used as a method for early detection of SCM more accurately than CMTS and SCC.

A cross sectional study of prevalence and risk factors associated with subclinical mastitis and intramammary infections, in dairy herds linked to milk collection centers in Rwanda

The objective of this cross-sectional study was to investigate prevalence, causative udder pathogens and their antimicrobial resistance (AMR), as well as cow and herd risk factors associated with subclinical mastitis (SCM = cows with at least one udder quarter with california mastitis test (CMT) score > 2) and intramammary infections (IMI) caused by Staphylococcus(S.) aureus or Non aureus staphylococci (NAS) in dairy cows linked to Milk Collection Centers (MCCs) in Rwanda. Screening for SCM with the CMT was done on 572 cows from 404 herds linked to two MCCs in each of four provinces. Milk from udder quarters with a CMT score ≥3 (scale 1–5) was sampled for bacteriological analysis. Antimicrobial resistance was evaluated in 60 selected S. aureus isolates. Multivariable mixed effect and ordinary logistic regression analyses were performed to identify cow and herd level risk factors associated with SCM, NAS or S. aureus IMI in cows. The prevalence of SCM was 37.3 % at quarter level and 62.0 % at cow level. Bacteria were isolated 73.7 % of the cultured milk samples, whereas 23.3 % were culture-negative and 3.0 % were contaminated. Staphylococcus aureus and NAS were the most prevalent pathogens, representing more than half of all bacteriological findings. Staphylococcus chromogenes and S. epidermidis were the most prevalent NAS species identified. Of the S. aureus strains 83.3 % were resistant for penicillin, 100 % for clindamycin and 20 % tetracycline. The risk factor analysis showed that an increased stage of lactation, dirty udder and legs in single cow herds and lack of calf suckling the dam, dirty udder and legs and lack of feeding cow after milking in multiple cow herds were significantly (P < 0.05) associated with an increased odds of SCM. Similarly, increasing stage of lactation in single cow herds, and housing cows in individual cattle kraal or on earthen floor and hand washing between cows during milking in multiple cow herds were associated with increased odds for NAS IMI. Poor hygiene of milking area in single cow herds and absence of foremilk stripping in multiple cow herds were significantly (P < 0.05) associated with increased odds for S. aureus IMI in cows. In conclusion, SCM prevalence was high across MCCs. The majority of identified pathogens were contagious in nature and they exhibited resistance to penicillin. Control of the identified risks factors and improved biosecurity through adoption of best practices, and farmer training could contribute to lowering SCM prevalence in Rwanda.

Subclinical mastitis in pastoralist dairy camel herds in Isiolo, Kenya: Prevalence, risk factors, and antimicrobial susceptibility

Mastitis is an important constraint to milk production in pastoralist camel (Camelus dromedarius) herds in Kenya. The objective of this study was to investigate the prevalence, risk factors, and bacterial panorama of subclinical mastitis (SCM) in pastoralist camel herds in Isiolo County, Kenya. Furthermore, antimicrobial susceptibility in udder pathogens was studied. A cross-sectional sample of 206 camels from 20 milking herds was screened using the California Mastitis Test (CMT), and quarter milk was subjected to bacterial culturing. Isolates were confirmed using MALDI-TOF mass spectrometry analysis, and antimicrobial susceptibility was determined using the broth microdilution method. Interviews focusing on herd management were conducted with camel owners. Subclinical mastitis, defined as a CMT score ≥ 3 (scale 1 to 5) and absence of clinical symptoms in the udder, were present in all visited herds. On the individual level, 46% of the camels had at least 1 quarter affected with SCM, and on the quarter level the prevalence was 26%. Intramammary infections (IMI) were common; out of 798 quarter milk samples, 33% yielded conclusive bacterial growth. The sensitivity and specificity of CMT for correctly identifying quarters with IMI were 82% and 92%, respectively. The most prevalent pathogen was Streptococcus agalactiae (72% of IMI-positive quarters), followed by non-aureus staphylococci (19%) and Staphylococcus aureus (13%). Antimicrobial susceptibility testing revealed that only a low proportion (4.9%) of Strep. agalactiae isolates was sensitive to tetracycline. For Staph. aureus, 59.1% of isolates exhibited sensitivity to penicillin. Skin lesions on the teats or udder were a risk factor for SCM. Increased age, parity, and stage of lactation were associated with increased risk of both SCM and IMI. Older camels with a blind teat or a previous history of mastitis were more likely to be infected with Strep. agalactiae. Hygiene routines for milking were largely absent in the observed herds, and knowledge of adequate milk handling was limited. The poor udder health is likely to depend on multiple factors, most prominently the within-herd maintenance of contagious udder pathogens, in combination with difficult sanitary conditions and lack of awareness among camel keepers. This study showed that in pastoralist camel herds around Isiolo town, SCM and IMI specifically caused by Strep. agalactiae are common udder health problems and are associated with increasing age, parity, and stage of lactation, and skin lesions on the teats and udder. Resistance to tetracycline in Strep. agalactiae was common. Control strategies specifically targeting SCM and adapted to pastorally managed camel herds need to be developed to reduce disease, combat antimicrobial resistance, and improve the livelihoods of pastoralists.

Short communication: Evaluation of α-linolenic acid–based intramammary nanosuspension for treatment of subclinical mastitis

The current study investigates the therapeutic efficacy of an α-linolenic acid (ALA, 18:3n-3)-based intramammary nanosuspension (ALA-NS) for treatment of subclinical mastitis. After confirmation of mastitis with the help of field-based testing, a total of 9 mixed-breed cows (23 udder quarter samples) were divided into 3 groups and treated with ALA-NS and cefoperazone intramammary suspension for 10 d. Subclinical mastitis on d 1 was confirmed through field-based tests such as pH, California Mastitis Test (CMT), Whiteside test (WST), and bromothymol blue test (BBT) scores. Treatment with ALA-NS (F1 and F2) exhibited significant effects on field-based parameters, along with curtailment of total microbial count [28 ± 3.16 (mean ± standard deviation) and 25 ± 4.24 cfu/50 µL] and somatic cell count (SCC; 3.9 and 2.8 log SCC cells/mL), respectively for ALA-NS F1 and F2, after 10-d treatment. The efficacy of ALA-NS was further affirmed using more stringent markers for inflammation (nuclear factor kappa-light-chain-enhancer of activated B cells, NFκB-p65), milk quality (sterol response element-binding protein-1c, SREBP-1c), and bacterial resistance (ubiquitin carboxyl-terminal hydrolase-1, UCHL-1) in milk samples. Treatment with ALA-NS (at 2 concentrations of ALA, F1 and F2) significantly decreased expression of NFκB-p65, SREBP-1c, and UCHL-1 after d 10 of treatment. Apparently, anti-inflammatory, antibacterial, peripheral analgesic properties of ALA could account for the therapeutic efficacy of the proposed regimen.

Practicability of somatic cell count and electrical conductivity as subclinical mastitis diagnostic tests in camels (Camelus dromedarius)

ABSTRACT Critical gaps exist in our understanding of the diagnostic reliability of subclinical mastitis tests in dromedary camels. Using a retrospective longitudinal cross-sectional approach, 191 lactating camels were randomly sampled from 47 camel herds to investigate at first the practicability of somatic cell count (SCC) and electrical conductivity (EC) tests as subclinical mastitis tests in camels through their validations by California mastitis test (CMT) score, and then through the subsequent employments of those objective means in assessing certain potential risk markers predisposing camels to this disease. Results indicate the reliability and validity of SCC test, in contrast to EC test, in distinguishing subclinical mastitic udders in camels, as demonstrated by the strong interrelationships ( r = 0.83 vs 0.12; R 2 = 0.80 vs 0.02), excellent agreement beyond chance (kappa coefficient = 0.76 vs 0.09) between SCC test and CMT scores, as well as by the high sensitivity of SCC test [Area Under Curve (AUC) = 0.94 vs 0.48] in distinguishing mastitic udders compared to the EC test. Based on the SCC test, the calculated overall prevalence rate for subclinical mastitis was 35 %, and the breed, parity, and lactation period were the only risk markers predisposing camels to subclinical mastitis. Collectively, it can be concluded that the objective SCC test possesses considerable diagnostic merit for early detection of subclinical mastitis in camels, while the EC test was non-satisfactory and non-diagnostic. Accordingly, it seems logical to base herd management decisions on SCC readings using the cut-off Log10SCC value of 5.67 (or SCC = 472.50 × 03 cells mL–1).

Genetic and genomic analyses underpin the feasibility of concomitant genetic improvement of milk yield and mastitis resistance in dairy sheep.

Milk yield is the most important dairy sheep trait and constitutes the key genetic improvement goal via selective breeding. Mastitis is one of the most prevalent diseases, significantly impacting on animal welfare, milk yield and quality, while incurring substantial costs. Our objectives were to determine the feasibility of a concomitant genetic improvement programme for enhanced milk production and resistance to mastitis. Individual records for milk yield, and four mastitis-related traits (milk somatic cell count, California Mastitis Test score, total viable bacterial count in milk and clinical mastitis presence) were collected monthly throughout lactation for 609 ewes of the Chios breed. All ewes were genotyped with a mastitis specific custom-made 960 single nucleotide polymorphism (SNP) array. We performed targeted genomic association studies, (co)variance component estimation and pathway enrichment analysis, and characterised gene expression levels and the extent of allelic expression imbalance. Presence of heritable variation for milk yield was confirmed. There was no significant genetic correlation between milk yield and mastitis traits. Environmental factors appeared to favour both milk production and udder health. There were no overlapping of SNPs associated with mastitis resistance and milk yield in Chios sheep. Furthermore, four distinct Quantitative Trait Loci (QTLs) affecting milk yield were detected on chromosomes 2, 12, 16 and 19, in locations other than those previously identified to affect mastitis resistance. Five genes (DNAJA1, GHR, LYPLA1, NUP35 and OXCT1) located within the QTL regions were highly expressed in both the mammary gland and milk transcriptome, suggesting involvement in milk synthesis and production. Furthermore, the expression of two of these genes (NUP35 and OXCT1) was enriched in immune tissues implying a potentially pleiotropic effect or likely role in milk production during udder infection, which needs to be further elucidated in future studies. In conclusion, the absence of genetic antagonism between milk yield and mastitis resistance suggests that simultaneous genetic improvement of both traits be achievable.

Subclinical Mastitis Survey on Milk Composition in Dairy Sheep in Kurdistan Region of Iraq

Mastitis is an inflammatory condition of the mammary gland, characterized by the changes in the physical characteristics of the udder or milk. A cross sectional study was carried out in June, 2017 to December, 2018 to estimate the effect of subclinical mastitis (SCM) on milk composition in dairy sheeps in Kafri city of Kurdistan region of Iraq. Milk samples were gathered from residences of 295 sheeps with subclinical mastitis (California mastitis test (CMT) positive and somatic cell counts (SCC) &gt;600,000 cells/ml in individual quarter foremilk), as well as from 50 healthy controls. Contrasted to the levels watched in milk from healthy quarters, milk from quarters with subclinical mastitis exhibited raised high chloride (&gt;0.12 in contrast with &lt;0.12 g/dl), pH (5.65 in comparison to 5.57), sodium (86.87 vs 47.81 mg/dl), albumin (4.52 in contrast with 1.75 g/dl), immunoglobulins (24.66% in comparison to 5.73%) and lactate dehydrogenase (LDH) activity (1344.14 vs 449.84 IU/L). In compare, reduced values were discovered for potassium (147.47 in comparison to 161.34 mg/dl), inorganic phosphorous (19.42 in comparison to 26.48 mg/dl), calcium (86.35 vs 121.12 mg/dl), β-lactoglobulin (30.22% in comparison to 52.18%) and α- lactalbumin (19.15% vs 24.52%). In this study, no changes were seen in blood serum LDH activity. Moreover, an increase in positive response to CMT was found to be accompanied by an almost proportionate increase in immunoglobulin values to 44.32% and reduce of α-lactalbumin levels in milk serum (p&lt;0.01). These alterations in LDH activity, pH, mineral concentrations and protein fractions in milk of quarters display the presence of tissue injury provoked by SCM. Therefore, these parameters can be used in the diagnosis of mastitis. The current study revealed that changes of the foremilk chemical composition are connected to the subclinical mastitis; and that mastitis progression of quarters (CMT scores) influenced protein fractions in milk.

The occurrence of mastitis and its effect on the milk malondialdehyde concentrations and blood enzymatic antioxidants in dairy cows

Early identification of mastitis is a serious challenge for dairy farmers and veterinarians in ensuring the health of an animal and the hygienic quality of the produced milk. The purpose of this study was to detect the occurrence and aetiology of mastitis in a dairy herd of 15 milked cows localised in a farm in west Slovakia. During the complex investigation, 606 quarter milk samples were examined (6 quarters were discarded) and classified based on the clinical status, the presence of abnormal udder secretions, the result of the California mastitis test (CMT), the somatic cell count (SCC) and the bacteriological identification of the pathogens causing the intramammary infection (IMI). The study was augmented by the detection of malondialdehyde (MDA) in the milk and the measurements of the blood enzymatic activities of glutathione peroxidase (GPx) and superoxide dismutase (SOD) as potential biomarkers for the udder health screening. A positive CMT score was recorded in 19.5% (118) of the examined quarters and 12.5% (76) of the quarters were infected with bacterial pathogens causing latent mastitis (LM; 1.3%), subclinical mastitis (SM; 8.3%), and clinical mastitis (CM; 2.9%). The most commonly isolated bacteria from the infected quarters were coagulase-negative staphylococci (55.2%), Staphylococcus aureus (11.8%) and streptococci (10.5%). The concentration of MDA and SCC were significantly higher from both the SM and CM cases than in the milk samples from the healthy cows, while the blood activities of SOD and GPx were lower in the cows with CM compared to the healthy cows. The higher MDA concentrations in the SM and CM milk observed in this study showed the presence of an oxidative stress in the infected milk, accompanied by a decrease in the antioxidative enzymatic activity in the blood of the cows. Therefore, the measurement of the milk MDA concentration and the activity of the blood SOD and GPx may prove insightful for the better screening of the udder health in the early diagnosis of mastitis.

Pharmacokinetics and pharmacodynamics of intramammary cefquinome in lactating goats with and without experimentally inducedStaphylococcus aureusmastitis

Values for pharmacokinetic variables are usually obtained in healthy animals, whereas drugs are frequently administered to diseased animals. This study investigated cefquinome pharmacokinetics in healthy goats and goats with experimentally induced mastitis. Five adult lactating goats received 75mg of cefquinome intramammary infusion using a commercially available product into one udder half in healthy goats and goats with clinical mastitis that was induced by intracisternal infusion of 100cfu of Staphylococcus aureus ATCC 29213 suspended in 5ml of sterile culture broth. Cefquinome concentrations were determined in plasma and skimmed milk samples using high-performance liquid chromatography (HPLC). Pharmacodynamics was investigated using the California Mastitis Test and pH of milk. Experimentally induced mastitis significantly increased the California Mastitis Test score and pH, and decreased the maximal cefquinome concentration and shortened the half-life in milk when compared to healthy goats. In conclusion, mastitis facilitated the absorption of cefquinome from the mammary gland of lactating goats and induced marked changes in milk pH, emphasizing the importance of performing pharmacokinetic studies of antimicrobial agents in infected animals.

Aetiology and prevalence of subclinical mastitis in dairy herds in peri-urban areas of Kigali in Rwanda

The aim of this cross-sectional study was to evaluate the prevalence of subclinical mastitis (SCM) and associated risk factors in dairy cows in peri-urban areas of Kigali, Rwanda, and identify causative udder pathogens. A sample of 256 cows from 25 herds was screened with the California Mastitis Test (CMT), and udder quarters with CMT score ≥ 3 (scale 1–5) were milk sampled for culture and final bacteriological identification with matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS). All resultant staphylococci species were tested for beta-lactamase production with the clover leaf method. In parallel, herd bulk milk somatic cell count (SCC) of each herd was analysed using a portable device, the DeLaval cell counter. The prevalence of SCM was 43.1% at quarter level and 76.2% at cow level based on CMT test. Multiparous, Holstein cows were 2.50 (C.I = 1.32–4.71) and 10.08 (C.I = 1.54–66.13) times more likely to contract SCM infection than primiparous animals or cows of other breeds, respectively. The median and mean SCC of all herds were 1108 × 103 cells/mL and 1179 × 103 cells/mL, respectively. The most prevalent pathogens were non-aureus staphylococci (NAS; 40.2%) followed by Staphylococcus aureus (22%) and less prevalent pathogens (6%). Samples with no growth or contamination constituted 30.4% and 1.4% of the diagnoses, respectively. The most prevalent species within NAS were S. epidermidis (38.2%) followed by S. sciuri (19.5%), S. chromogenes (9.8%), and nine less prevalent NAS species (32.5%). Out of 209 staphylococci isolates, 77% exhibited beta-lactamase production. The study shows that there is high prevalence of SCM and high herd bulk milk SCC in herds in Kigali, indicating udder health problems in dairy cows. Additionally, beta-lactamase production among staphylococci species was common. Improved milking hygiene and application of biosecurity measures, or a complete mastitis control plan, is required to lower the prevalence of SCM and minimize the spread of pathogens among dairy cows.